Abstract: Novel, chiral diarsine compounds, which are present in the (R)- or (S)- or (rac)-form, of the formula ##STR1## wherein R signifies an optionally substituted aryl from the group of phenyI, naphthyl, furyl and thienyl; C.sub.3-8 -cycloalkyl or C.sub.1-8 -alkyl;R.sup.1, R.sup.2, R.sup.3 each independently signify C.sub.1-8 -alkyl, C.sub.1-8 -alkoxy, aryloxy, F or Cl,R.sup.2 and R.sup.3 each independently also signify hydrogen orR.sup.1 and R.sup.2 together signify tetramethylene or a benzo or benzofuro system or dioxymethylene on the respective benzene ring; orR.sup.2 and R.sup.3 together signify dioxymethylene,and the manufacture of the diarsine compounds of formula I, as well as complexes of the compounds of formula I with Group VIII metal and their use for enantioselective reactions.

Abstract: The present invention is concerned with novel optically active phosphorus compounds of the general formula ##STR1## wherein R and R.sup.1 each independently signify hydroxy, a protected hydroxy group, lower alkyl or lower alkoxy andR.sup.2 to R.sup.5 each independently signify alkyl with 3 to 7 carbon atoms, cycloalkyl or aryl or R.sup.2 and R.sup.3 or R.sup.4 and R.sup.5 together with the phosphorus form a group of the formula ##STR2## wherein R2 and R3 are different when R4 and R5 are the same, and R4 and R5 are different when R2 and R3 are the same,the manufacture of such compounds, their use for enantioselective reactions, such as, e.g., asymmetric hydrogenations, enantioselective hydrogen displacements in prochiral allylic systems and the like, as well as complexes of the compounds of formula I with Group VIII metals.

Abstract: Novel, racemic and optically active phosphorus compounds of the formula ##STR1## wherein R signifies lower alkyl, lower alkoxy, hydroxy or a protected hydroxy group, R.sup.1 and R.sup.2 are different from each other and represent lower alkyl, cycloalkyl, aryl, a five-membered heteroaromatic or a group of the formula ##STR2## are described. The compounds of formula I are useful in the form of complexes with a metal of Group VIII as catalysts for asymmetric hydrogenations and for enantioselective hydrogen displacements in prochiral allylic systems.

Abstract: Novel chiral phosphorus compounds of the formula ##STR1## wherein R signifies lower alkyl, R.sup.1 signifies phenyl and R.sup.2 and R.sup.3 signify hydrogen or lower alkoxy,which are suitable in the form of complexes with a metal of Group VIII as catalysts for asymmetric hydrogenations and for enantioselective hydrogen displacements in prochiral allylic systems.

Abstract: A process for the resolution of racemic diphosphine oxides into the optically active antipodes by reacting the racemate with a resolving agent comprising using a carbamate or thiocarbamate of an optically active .alpha.-hydroxycarboxylic acid or .alpha.-aminocarboxylic acid as the resolving agent.

Abstract: Optically active pyrimidines of the formula ##STR1## wherein Z is --(CH.sub.2).sub.n -- or --(CH.sub.2).sub.n --O-- wherein n is an integer of 1 to 4 and each of the symbols X is a nitrogen atom and each of the symbols Y is --CH-- or each of the symbols Y is a nitrogen atom and each of the symbols X is --CH--,useful for electro-optical purposes, as well as liquid crystalline mixtures for electro-optical purposes containing compounds of the formula Ia and/or Ib, are described.The compounds of formulas Ia and Ib are useful for electro-optical purposes, for example, in electro-optical apparatuses.

Abstract: Phenyl-pyrimidines of the formula ##STR1## wherein R.sub.1 and R.sub.2 are as hereinafter set forth, are described. The end products are useful as liquid crystals.

Abstract: Compounds of the formula ##STR1## wherein when X is nitrogen, Y and Z are --CH--; or when Y is nitrogen, X and Z are --CH--; or when Z is nitrogen, X and Y are --CH--; and one of R.sub.1 and R.sub.2 is cyano and the other is straight-chain alkyl of 1 to 7 carbon atoms, straight-chain alkoxy of 1 to 7 carbon atoms or straight-chain alkanoyloxy of 2 to 7 carbon atoms,Prepared by a variety of methods, are described. The compounds of the invention are useful as components of nematic mixtures.

Abstract: Phenyl-pyrimidines of the formula ##STR1## wherein R.sub.1 and R.sub.2 are as hereinafter set forth, are described. The end products are useful as liquid crystals.